主頁面（要求刷新的頁面）要求每一分鐘刷新一次系統時間
//建立httpRequest物件getSystemTime.jsp //取得系統目前的時間，也就是輸出結果的頁面
<%@ page language="java" %>
<%@ page contentType="text/html;charset=GB2312" %>
<%@ page import="java.util.Date"%>
<%@ page import="java.sql.Timestamp"%>
<%@ page import="java.io.IOException"%>
<%
Date d = new Date();
Timestamp ts = new Timestamp(d.getTime());
String result = ts.toString().substring(0,16);
out.write(result,0,result.length());
%>
ajax.js
function makeRequest(url) {
http_request = false;
if (window.XMLHttpRequest) {
http_request = new XMLHttpRequest();
if (http_request.overrideMimeType){
http_request.overrideMimeType('text/xml');
}
} else if (window.ActiveXObject) {
try{
http_request = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
try {
http_request = new ActiveXObject("Microsoft.XMLHTTP");
} catch (e) {
}
}
}
if (!http_request) {
alert("您的瀏覽器不支援目前操作，請使用IE 5.0 以上版本!");
return false;
}
//定義頁面呼叫的方法init,不是init();沒有();
http_request.onreadystatechange = init;
http_request.open('GET', url, true);
//禁止IE快取
http_request.setRequestHeader("If-Modified-Since","0");
//傳送數據
http_request.send(null);
//每60秒刷新一次頁面
setTimeout("makeRequest('"+url+"')", 60000);
}
function init() {
if (http_request.readyState == 4) {
if (http_request.status == 0 || http_request.status == 200) {
var result = http_request.responseText;
if(result==""){
result = "系統時間取得失敗";
}
document.getElementById ("sysTimeShow").innerHTML="平台系統時間："+result;
} else {//http_request.status != 200
alert("請求失敗!");
}
}
}